1. The Field of the Invention
The present invention relates to wipers having a wiper blade and an additional movable scrubber element attached thereto.
2. The Relevant Technology
Safety is a critical issue in today's world of fast vehicles. In particular, an operator of an automobile must be able to clearly view everything happening around the vehicle and make split-second decisions based on what he sees. In particular, the automobile operator must be able to clearly see through the windshield to view the road ahead. If the view through the windshield becomes blocked or even obscured for whatever reason, it can impact the driver's view and create a dangerous situation.
To help provide clear vision through the windshield, almost all motor vehicles sold today come with a standard set of windshield wipers. Conventional windshield wipers typically include a wiper blade which is attached to a wiper support structure designed so as to cause the wiper blade to remain in contact with the windshield surface. The wiper support structure is attached to a wiper arm that attaches the windshield wiper to the motor vehicle. During use, the wiper arm causes the wiper support structure to move back and forth across the windshield.
A conventional windshield wiper blade is approximately 0.030 inches (0.7 mm) in width and is composed of smooth rubber held in contact with the automotive windshield by spring tension. It was specifically designed to squeegee fluid from the windshield's surface, thereby providing clear vision through the windshield during wet weather. To accomplish this function, the material of the conventional wiper blade is designed to be soft, flexible and smooth.
As noted above, if the view through the windshield becomes blocked or even obscured for any reason, it can impact the driver's view and create a dangerous situation. This can occur, for example, when the windshield wiper stops working or when the wiper blades become worn and lose their ability to squeegee, as discussed above. This can also occur when something hits the windshield that the windshield wiper is not able to remove by the squeegee action, even when the windshield is wet. The latter can occur, for example, when a car passes through a swarm of insects that splatter all over the windshield. This can also occur when ice builds up on the windshield, such as when the vehicle has been left outside for an extended period of time in the winter.
Due to the compound curvatures that vary over most windshields, the wiper support structure is not enough, of itself, to cause the wiper blade to remain in contact along its entire length with the windshield as the wiper support structure moves across the windshield. To combat this inherent flaw, the wiper blade is made of a flexible material, such as rubber or the like, and is very thin. The flexibility and thinness of the wiper blade allow the wiper blade to follow the contours of the windshield, making up for the inherent flaw of the wiper support structure. As a result, the wiper blade squeegees the windshield as the wiper blade passes over the windshield, thereby removing liquid, such as rain, away from the forward field of view of the driver. The squeegee action generally causes other light debris, such as dust, leaves, or light dirt, to also be removed with the water. Removal of liquid and debris, of course, is necessary so the driver can see the road ahead while driving during inclement weather.
However, due to its design, the conventional windshield wiper has a number of inherent flaws. For example, the squeegee action is not particularly useful in removing debris when the windshield is dry. Squeegees are designed to remove liquids. When the surface is dry, the squeegee may simply flex or pass over the top of debris and can make matters worse by smearing the debris or causing streaks to occur. For this reason, conventional automobiles include fluid that can be sprayed onto the windshield. When the windshield becomes dirty while there is no precipitation, the driver can activate a washer pump that causes washer fluid to flow through a fluid line and spray onto the windshield to provide liquefaction of the debris to help the windshield wipers squeegee the debris. This works well on certain debris, such as, e.g., dust, light dirt, and light road salt.
Even with liquefaction, however, certain types of debris may still be non-removable from the windshield. For example, insect residue, bird droppings and tree sap, among other things, can adhere to the windshield almost instantaneously and may not be removable by the squeegee action of the windshield wiper.
To allow the squeegee action to take place, the wiper blade must be flexible and thin. As a result, the width of the portion of the wiper blade that contacts the windshield is very small, as noted above. This means that for every sweep of the conventional windshield wiper over the windshield, the wiper blade will contact any one spot of the windshield only very briefly and with little force. As a result, debris that has adhered to the windshield, such as, e.g., insect residue, bird droppings, and sap, will remain on the windshield even after repeated attempts to remove the debris.
In fact, in many cases, repeated attempts to remove the debris by the conventional windshield wiper has a detrimental effect on the clarity of the windshield. The foreign matter tends to be smeared over a larger surface of the windshield and further foreign matter will accumulate over the period of time the vehicle is in motion, further degrading the clarity of the windshield resulting in reduced visual clues to the operator.
A further complication of cleaning a vehicle's windshield while the vehicle is in motion is the variety of the organic compounds and the viscosity of the organic compounds striking the windshield. For example, insects that are comprised of chitin, which is only partially dissolved in the windshield cleaning cycle, results in a smearing/spreading effect as the windshield wiper attempts to squeegee the partially dissolved viscous insect material from the windshield. The spreading effect caused by the squeegee action of the windshield wiper reduces the thickness of the insect material. This, coupled with the airflow over the vehicle, will evaporate any liquid located within the insect that is capable of evaporation, resulting in a dry and hard organic residue. This effect begins at the point of windshield impact in a line consistent with the travel of the windshield wiper, and is commonly referred to as smearing.
A further consideration is that by design, a conventional windshield wiper blade tends to squeegee all of the applied cleaning solution from the surface of the windshield on the first wiper sweep after activation. The time available for the cleaning solution to work is equivalent to approximately 0.75 second. The removal of the cleaning solution from the windshield is further facilitated by the airflow moving over the windshield caused by the motion of the vehicle through the atmosphere. At interstate speeds, a substantial portion of the cleaning solution may fail to strike the windshield and is carried away or evaporated by the high-speed airflow.
Finally, exacerbating the problems discussed above, due to the small width of the wiper blade, the blade can wear out quickly and/or lose its smooth edge so as to lose its ability to squeegee, thereby causing the blade to not be effective in removing water, let alone debris, from the windshield.
Various attempts have been made to design windshield wipers that will solve the above problems. For example, windshield wipers have been designed that include scrubbing pads meant to passively scrub the windshield as the windshield wiper passes back and forth over the windshield. The scrubbing pads are supposed to help remove the foreign matter from the windshield, but do not appear to be enough to remove all of the foreign matter. Applicant notes that he is aware of no commercially available wiper that even has a scrubbing pad.
As a result, many drivers operate their vehicles even when the windshields of those vehicles are at least partially obstructed from debris on the windshield that the wipers are not able to remove. This severely impacts the safety of the drivers.
Another problem with conventional wipers is that they are not designed to remove ice buildup on the windshield, thereby causing further safety problems in cold weather. As a result, drivers will either drive with ice obscuring their vision or start their vehicles and turn on the heater so the windshield can be heated to melt the snow and ice from the windshield before driving. For the ice to melt, the engine must first warm up so that waste heat from the engine can then be directed toward the inside surface of the windshield. After another significant amount of time, the ice melts due to the warmth of the windshield. As a result, the vehicle engine must idle for a significant amount of time to remove the built up ice. This wastes fuel and releases a significant amount of exhaust products, such as, e.g., carbon dioxide into the atmosphere.
In fact, according to some estimates, each year in the United States during inclement or cold weather hundreds of millions of tons of carbon dioxide are released into the atmosphere by internal combustion engines that are idling for the purpose of “warming up”. This widely accepted practice is detrimental to engine longevity and harmful to the environment.
Accordingly, what is needed are windshield wipers that alleviate one or more of the above problems.